Sentence AXIOM-OF-REGULARITY

Slots on this instance:

Documentation:
every non-empty set has an element with which it has no members in common.
Instance-Of: Sentence
Defining-Axiom: 
'(Forall (?S)
         (=> (Not (Empty ?S))
             (Exists (?U) (And (Member ?U ?S) (Disjoint ?U ?S)))))

Notes: